Robust Thevenin Equivalent Parameter Estimation for Voltage Stability Assessment

This letter presents a robust approach to accurate estimation of Thevenin equivalent (TE) parameters using phasor measurement unit (PMU) data for online voltage stability assessment. The TE parameter estimation is formulated as a worst-case robust least squares problem to take PMU uncertainties into account. A second-order cone programming technique is then utilized to solve the problem. Case studies on several IEEE standard networks and a practical power system, along with comparative results, illustrate the effectiveness and robustness of the presented approach.